Stainless steel hardness testing should take stainless steel seamless pipe’s mechanical properties into account, which relates to the stainless steel as raw material for deformation, stamping, cutting and other processing performance and quality. Therefore, all the seamless steel pipe need to be carried out mechanical performance testing. Mechanical performance testing methods are mainly divided into two categories, one is the tensile test, one is the hardness test.
The tensile test is to make the seamless steel pipe into a sample, pull the specimen to the fracture on the tensile tester, and then measure one or several mechanical properties, usually only to determine the tensile strength, yield strength, elongation at break and rate of reduction in area. Tensile test is the most basic mechanical properties of metal materials test methods, almost all of the metal material, as long as the mechanical properties are required, are provided for the tensile test. Especially those which are not easy to carry out the hardness test of the material, tensile test as the only means of mechanical performance testing.
Hardness test of stainless steel seamless pipe is a hard indentation according to the provisions of the conditions slowly pressed into the sample surface, and then test the depth or size of indentation, in order to determine the size of the material hardness. The hardness test is the simplest, fastest and easiest way to implement the mechanical properties test. Hardness test is non-destructive, the material hardness value and the tensile strength value between the approximate conversion relationship. The hardness value of the material can be converted into tensile strength value, which has great practical significance.
Since the tensile test is not easy to test and is easily converted from hardness to strength, it is increasingly difficult to test the hardness of the material and test its strength. In particular, due to the continuous improvement of hardness manufacturing technology and innovation, some can not directly test the hardness of the material, such as seamless steel pipes, stainless steel plate and stainless steel strip, etc., are now possible to directly test the hardness. Therefore, there is a tendency for a hardness test to gradually replace the tensile test.
Most of the national standards for stainless steel materials also specify tensile tests and hardness tests. For those materials that are not difficult to carry out hardness tests, such as seamless steel tubes, only tensile tests are specified. In the stainless steel standard, the general provisions of the cloth, Los, Victoria three hardness test methods, determination of HB, HRB (or HRC) and HV hardness values, the provisions of the three hardness values can only be measured one. In particular, the company developed the latest portable Rockwell hardness, pipe Rockwell hardness tester, can be thin to 0.05mm stainless steel plate, stainless steel strip and fine to 4.8mm seamless steel pipe for fast and correct hardness testing, making In the past difficult to solve the problem solved in the country.